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= nng_cv_wake(3supp)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt). A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//
== NAME
nng_cv_wake - wake all waiters
== SYNOPSIS
[source, c]
----
#include <nng/nng.h>
#include <nng/supplemental/util/platform.h>
void nng_cv_wake(nng_cv *cv);
----
== DESCRIPTION
The `nng_cv_wake()` wakes any threads waiting for the condition variable _cv_
to be signaled in the <<nng_cv_wait.3supp#,`nng_cv_wait()`>> or
<<nng_cv_until.3supp#,`nng_cv_until()`>> functions.
The caller must have have ownership of the mutex that was used when
_cv_ was allocated.
NOTE: The caller should already have set the condition that the waiters
will check, while holding the mutex.
TIP: This function wakes all threads, which is generally safer but can
lead to a problem known as the "`thundering herd`" when there are many
waiters, as they are all woken simultaneously.
See <<nng_cv_wake1.3supp#,`nng_cv_wake1()`>> for a solution to this problem.
== RETURN VALUES
None.
== ERRORS
None.
== SEE ALSO
<<nng_cv_alloc.3supp#,nng_cv_alloc(3supp)>>,
<<nng_cv_until.3supp#,nng_cv_until(3supp)>>,
<<nng_cv_wait.3supp#,nng_cv_wait(3supp)>>,
<<nng_cv_wake1.3supp#,nng_cv_wake1(3supp)>>,
<<nng_mtx_alloc.3supp#,nng_mtx_alloc(3supp)>>,
<<nng_mtx_lock.3supp#,nng_mtx_lock(3supp)>>,
<<nng_mtx_unlock.3supp#,nng_mtx_unlock(3supp)>>,
<<nng.7#,nng(7)>>
|
